The present invention relates to a grinding machine for machining inner surfaces, especially cylindrical inner bores, of workpieces; the machine includes a base or bench, at least one headstock for workpieces, and a carriage that supports a grinder unit and is displaceably guided on the bench via guide means operatively connected thereto.
With heretofore known grinding machines of this type, the grinder unit, which rotatably drives the grinding tool, is supported by a cross slide that can be moved axially back and forth on longitudinal guides, and can be adjusted at right angles thereto by means of a transverse guide. A headstock is generally provided for holding the workpiece; a chuck for receiving the workpiece is rotatably supported in the headstock.
In order to obtain good results, very high requirements are set for the stability and precision of the guides; this, of course, involves correspondingly high structural and manufacturing expenses
The roundness which can be achieved for the workpiece bore which is to be machined depends to a large extent upon how precisely the grinder axis can be aligned and guided relative to the axis of the workpiece. In this connection, prior to machining the workpiece bore, the guides must be manually aligned.
Errors which occur during the machining, and which are essentially caused by non-uniform abrasion of grinding material at the workpiece, is attempted to be kept within narrow limits by frequent adjustment or truing of the tool. However, this does not always produce satisfactory results. Furthermore, an additional drawback in each case is that the frequent truing process considerably reduces the service life of the tool; in addition, expensive grinding material is lost, especially when tools containing diamond or boron nitride grinding material are used.
It is an object of the present invention to provide a grinding machine of the aforementioned general type which, with a simple structure, permits a precise alignment of the grinder axis relative to the axis of the workpiece.